1. Field of the Invention
The present invention is generally directed to systems, apparatuses, and methods for exchanging information. The present invention is more particularly directed to systems, apparatuses, and methods for exchanging information in a secure manner.
2. Background Art
The replacement of secret keys is a central problem in key management. The danger of a key being compromised increases with the duration of its use. (See W. Fumy and P. Landrock, “Principles of Key Management,” IEEE J. Sel. Areas Commun., vol. 111, no. 5, pp. 785-793, June 1993, the entirety of which is incorporated by reference herein.) For example, each act of authentication requires partial revelation of a secret key which can result in eventual compromise. (See U. M. Maurer, “Authentication Theory and Hypothesis Testing,” IEEE Trans. Inf. Theory, vol. 46, no. 4, pp. 1350-1356, July 2000, the entirety of which is incorporated by reference herein.) Therefore, it is important to replace the key before it is compromised. However, unless efficient key replacement algorithms are used, significant overhead may be introduced into the system.
Secret keys are often used in symmetric encryption. Symmetric keys give the most security per bit (see R. D. Silverman, “A Cost-Based Security Analysis of Symmetric and Asymmetric Key Lengths,” RSA Labs., Bulletin 13, November 2001, the entirety of which is incorporated by reference herein), followed by elliptic curve keys (see V. S. Miller, “Use of Elliptic Curves in Cryptography,” Lecture notes in Computer Sciences (CRYPTO 85), vol. 218, pp. 417-426, 1985; N. Koblitz, “Elliptic Curve Cryptosystems,” Mathematics of Computation, vol. 48, no. 177, pp. 203-209, January 1987, the entirety of each of which is incorporated by reference herein), and finally Rivest-Shamir-Adleman (RSA) keys give the least security per bit (see R. L. Rivest, A. Shamir, and L. Adleman, “A Method for Obtaining Digital Signatures and Public-Key Cryptosystems,” Communications of the ACM, vol. 21, no. 2, pp. 120-126, 1978, the entirety of which is incorporated by reference herein). That is, for the same length key, a symmetric key system is harder to defeat than asymmetric, public-key based systems. Symmetric keys are typically used in high-rate applications since symmetric encryptions are generally much faster than asymmetric encryptions.
Traditional key replacement strategies fall under three paradigms:                1) Distribute secret keys over a secure channel that has limited availability.        2) Use third parties to help manage keys. This includes the use of public key infrastructures and key authorities.        3) Negotiate keys over an insecure channel.Nonetheless, there exists a need for key replacement methods, and applications thereof, that not only meet security requirements, but also are efficient to allow more-frequent key replacements.        